To me, Tizen is basically what MeeGo would be if you ripped out all the good bits (Qt with QML, full Linux compatible distribution, etc) and really only does what Firefox OS can do. HTML5 is not really a good platform for applications. No matter how much some people want it to be.

Not a fair point, when you see that Nokia themselves have voluntarily took every step to bury it. At the time where the infamous "burning platform" memo which started this process was released, the Symbian ecosystem was very much alive, largely dominating the smartphone industry, and still growing.

While there were some reasoned arguments for Nokia to switch to another OS, be it Meego or Windows Phone, in the long run, concerns about Symbian's short-term (5-year) market success were not one of them. Even the current WP strategy could have kept the company flying on Symbian sales a lot longer, if the management did not take the option of throwing the company's assets in the water and yelling them to learn to swim quickly.

One theory is that Samsung want to sweep Tizen for Android on their phones, and hence need same UI as for Android. (Add to it Samsung own app store, and compatibility with Android apps, and Samsung could defeat Google over singe night...)

Other is that using current UI from Android was easy, and could cut "deliver to the market" time.

As for C++, every time I look at their documentation with hopes they got something sane, it brings back bad memories of Symbian C++ with their two step construction, placement new, naming conventions to denote method behaviors and many other headaches.